MINNEAPOLIS (KARE 11) - Two persistent Minneapolis police officers clung to a cold case of a murder in 1980. The result? Murder charges against a man in Kansas using DNA evidence.

"They have that tenacity," commented Lt. Rick Zimmerman of the Minneapolis Homicide Unit. "They prefer the slower, methodical approach to doing homicides and they are good at it."

Zimmerman said he was proud of Sgt. Barb Moe and Sgt. Tammy Diedrich for their pursuit of the killer of Mary Catherine Steinhart, 22, on Nov. 25, 1980. Moe and Dietrich picked up the old case in 2008. It had lain mostly unmoved since the 1980's.

"As you recall, in the mid 90s," Zimmerman explained, "when DNA (evidence) was just getting going, you had to have quite a bit of blood or quite a bit of body fluids in order to test it. Now it is just amazing. The technology of "touch" DNA. If a suspect just touches something, they sometimes can pick it up at the State Crime Lab."

Aware of the advances in DNA technology at the Minnesota Bureau of Criminal Apprehension Laboratory in Saint Paul, the detectives searched the old files and evidence locker for items that had not been considered testable with the old methods.

"Sometimes, sadly in some cases, over the years, a piece of property, a piece of evidence gets lost or destroyed," said Zimmerman.

That was not the case in the Steinhart matter.

"We were fortunate in this case, that the sheets, the fingernail fibers, the fibers that were found under the fingernails, were all preserved in paper," said Zimmerman. "So, they were dried properly. Sometimes things were put in plastic years ago, when DNA was not even thought of and those items were destroyed."

There is another reason why the DNA evidence from the Minneapolis case was not matched on a national DNA database until recently. The DNA profiles were simply not there.

"It took several years to do that because some states are slower than others at entering the evidence," said Zimmerman. "In California, (Robert Skogstad) was arrested in 1988 and his information was not entered into the computer system for a national search for nearly 20 years."

The detectives learned that Skogstad had lived in the Twin Cities in the 1980s and had worked as a caretaker in Steinhart's apartment building where the crime occurred. In 1988, Skogstad was convicted of burglary and forcible rape in California and, like the Steinhart killing, a pillow was used to cover the victim's face during the attack. DNA profiles were taken. Still, two decades would pass before that data would be available to Minnesota's lab and the tenacious detectives.

It was not until 2010, that the match was found in the enlarged DNA database. Even after the new DNA profile led detectives to their suspect, there was one more step to take.

In February 2011, Sergeants Moe and Diedrich journeyed to Edgerton, Kansas, where Skogstad was living, to confront him and obtain new DNA. They obtained a cheek swab, although Skogstad denied living in the Girard Avenue South Building and denied a sexual relationship with the victim. He could not explain the presence of his DNA on the victim and in her apartment.

"After the match was made through the search, in Minnesota and California, you have to still contact the person and you have to still do a search warrant to collect DNA from that person. So, there is no mistaking that the DNA matches or it does not match," said Zimmerman.

In August, the Hennepin County Attorney's office issued a warrant for Skogstad's arrest. The 57-year-old was arrested in September in Kansas. He has been charged with murder in the second degree and, as of Wednesday, he is being held in jail in Kansas.